Four suspects accused in the killing of Redskins Pro Bowl safety Sean Taylor have filed written not-guilty pleas to first-degree felony murder and armed-burglary charges.The arraignment hearing is set for tomorrow.

* Cowboys safety Roy Williams lost his appeal and will be suspended from Saturday night’s game at Carolina as punishment for his repeated use of the horse-collar tackle . . . Despite a sore thumb, the Cowboys expect Tony Romo to start.

* Sen. Patrick Leahy (D-Vt.) and Sen. Arlen Specter (R-Pa.), members of the Senate Judiciary Committee, sent a letter to the NFL yesterday threatening to reconsider the league’s antitrust exemption if it doesn’t make games on the NFL Network available to more viewers.

BASEBALL: Redman to sign

The Rockies agreed to one-year contracts with lefty Mark Redman and right-hander Kip Wells, formerly of the Cardinals . . . Free-agent pitcher Carlos Silva, formerly of Minnesota, and the Mariners are close to completing a four-year contract . . . Catcher Michael Barrett and the Padres have agreed to a $3.5 million, one-year contract.

HOOPS: Pistsons stop Celts

Chauncey Billups hit two free throws with a tenth of a second left to lead the Pistons to a 87-85 win over the Celtics last night. The loss was Boston’s first at home this season.

* Houston star Tracy McGrady left last night’s game against Orlando with a sore left knee. He missed 10 of 11 shots and was limping noticeably in the first half. The Magic won, 97-92.

* Dexter Gray led five Iona players in double figures with 15 points as the Gaels (4-7) posted a 76-66 win over St. Francis (3-7) last night in Loretto, Pa. Under first-year coach Kevin Willard, Iona doubled its victory total from last season when it went 2-28.

NHL: Adams suspended

Carolina forward Craig Adams was suspended two games without pay for hitting Toronto’s Alex Steen with his stick. Adams will forfeit $6,417.12, with the money going to the Players’ Emergency Assistance Fund.